Individuals choose to use contraception for many reasons:
●All contraceptives provide control over the timing of pregnancy and avoidance of unintended pregnancy
●Condoms provide protection from sexually transmitted infections
●Hormonal contraceptives provide noncontraceptive health benefits (table 1)
A systematic review estimated contraceptive prevalence among women of reproductive age who were married or in a union was 63 percent worldwide and 77 percent in the United States . Nevertheless, unintended pregnancy is a common problem. In a study from the Guttmacher Institute using data from several sources, 49 percent of the 6.7 million pregnancies in the United States in 2006 were unintended . About 5 percent of women of reproductive age had an unintended pregnancy that year, comprising 3.2 million pregnancies. The demographic characteristics of these women are shown in the table (table 2). Forty-three percent of the unintended pregnancies were terminated. These alarmingly high statistics occurred even though most women reported using some form of contraception . The high rate of unintended pregnancy despite contraception highlights the importance of understanding contraceptive efficacy in terms of typical, rather than perfect, use (see 'Effectiveness' below).